The Girls' High School originated as the Girls' Endowed School, which was opened in 1904 in a room at the School of Science and Art in Lansdown. The first headmistress was Miss D.M. Beale, a niece of the famous Principal of Cheltenham Ladies' College.
By 1907, there were 70-80 pupils, and in 1912, the school moved to new buildings in Beard's Lane, close to Marling School. The site had previously been used for a Boys' Craft School, built in 1909-10, and these buildings are now part of the school. The new High School buildings were designed in a neo-Georgian style, and built in brick with local stone dressings, by the County Council's architect, R.S. Phillips. They are perhaps his most successful designs.
The hall building was added to the west of the original block in 1939, and a Postmodern science block was added in 1993, to designs by Dancey & Meredith. In 1971, the school had 800 pupils.